Typically, maple water is transformed into maple syrup in an evaporator, standardly fired by wood, oil or gas. The water is heated until it boils. From the time the maple water is poured into the evaporator to the time it turns into syrup, it undergoes a complex chain of chemical reactions which produce the characteristically maple color and flavor. Typically, around 40 liters of maple water are evaporated to produce 1 liter of syrup. Most of the water in the maple water evaporates during this process, leaving concentrated maple syrup. Maple water has a sugar content comprised between about 1 and 4 Brix, while maple syrup has a sugar content of about 66 Brix.
Generally, the evaporator consists of one or more pans that are placed over a firebox referred to as an arch. The pans are divided into sections to separate the more concentrated maple water from the more dilute. The sections are not closed, so that the maple water can move freely as the water evaporates therefrom. A flat bottomed pan is referred to as the syrup pan or finishing pan. Syrup reaches its final concentration in this pan. Flues in the bottom of the sap pan greatly increase the surface area for heating. Hot gasses from the fire pass between the flues. The flue pan is positioned toward the back of the firebox. The maple water enters the flue pan. The syrup pan is placed over the front of the firebox above grates in a wood fired arch as we see below. The syrup pan and flue pan are connected so that the flow is continuous. The maple water in the pans is about 2 inches deep during active boiling. The amount of steam that rises is substantial.
The evaporation process is highly energy consuming, energy being dissipated mainly as water vapor.
There is a need in the art for a maple water evaporator system.